What happened
On June 18, 1985, a student pilot accompanied by his flight instructor was engaged in a local training flight. The objective of the mission involved practicing emergency procedures, specifically focusing on autorotation techniques essential for helicopter safety.
Prior to completing the full scope of the training mission, the instructor directed the student to execute a 180-degree autorotation. This maneuver is designed to simulate an engine failure and teach the pilot how to maintain rotor RPM during descent to ensure a safe landing.
During the execution of this specific maneuver, the main rotor RPM was permitted to decay into the critical range. The loss of adequate rotor speed resulted in a hard landing upon touchdown. The impact forces were sufficient to subsequently destroy the helicopter.